Due South with the British Antarctic Survey

Linux now facilitates scientific research in the Atlantic Ocean and Antarctica.

A cold and windy September afternoon
marks the start of the fifth Atlantic Meridional Transect (AMT)
experiment aboard the British Antarctic Survey (BAS) research
vessel RRS James Clark Ross. Each year the
ship sails from the UK to the Falkland Islands in September en
route to service the UK Antarctic research bases. Jim (our UNIX
support engineer) is busy fastening down his trusty Toshiba laptop
(Tecra 730XCDT with 48MB) in his cabin on board James
Clark Ross in preparation for the inevitable bad
weather. Ahead of us lie six weeks of precision ocean-atmosphere
measurements, near real-time data processing, heated debate,
troubleshooting and, hopefully, some scientific discovery.
Fortunately, we have both chosen one of the most versatile and
reliable operating systems at hand to maximize our output during
this experiment—Linux. This article discusses
the impact of Linux, which is now routinely used at BAS and during
the AMT experiments. (See http://www1.npm.ac.uk/amt/ for more
information on the AMT project.)

The RRS James Clark Ross (shown in
Figure 1) was launched in 1990 and is one of the world's most
complex marine research vessels, incorporating over 400 square
meters of scientific laboratory space. It was named after the
scientist and polar explorer Admiral Sir James Clark Ross, RN
(1800-1862), who in February 1842 reached 78.9 degrees S—a record
which remarkably stood well into the 20th century.

Figure 2 shows the track taken by the James Clark
Ross during the and AMT-5 cruise superimposed on a
monthly composite satellite image of Chlorophyll
a derived from the Sea-viewing Wide
Field-of-view Sensor (SeaWiFS) carried on the SeaStar spacecraft.
Different types of phytoplankton have characteristically different
concentrations of chlorophyll and are, therefore, different in
color. By measuring the color of the ocean with the SeaWiFS
instrument, estimates of the amount and general type of
phytoplankton in specific regions can be made as shown in Figure 2.
An extensive web site provides a wealth of information on the
SeaWiFS mission at
http://seawifs.gsfc.nasa.gov/SEAWIFS.html.

The ocean-atmosphere measurements taken during the AMT
cruises are fundamental for the calibration, validation and
interpretation of remotely sensed observations, including
sea-surface temperature, wind speed, atmospheric water vapour and
ocean colour (which can be related to bio-optical processes)—all
of which are vital for ongoing climate research. Figure 3 shows the
instrument cluster mounted on the forward mast of the
James Clark Ross which measures, among other
things, sea-surface temperature (using an infrared radiometer),
solar radiation, wind speed and direction, air temperature, radar
backscatter (a measure of surface roughness) and humidity. All of
these measurements are used to investigate the processes, occurring
at the air-sea interface, which in many cases define the signal
actually measured by the satellite instruments. (See
http://www1.npm.ac.uk/amt/ for more information on the AMT
project.)

From a system engineer's point of view, the main requirement
of an operating system is that it integrate with the existing
computing infrastructure available on (in this case) BAS ships and
also at Antarctic bases as well as at headquarters. Since the
majority of instruments are logged to Sun SPARC workstations, it
makes sense to run an OS which allows NFS mounts to the data areas
the workstations create. Many users require the ability to perform
data processing locally without having to place extra strain on the
data-logging workstations. As most of this is undertaken using
shell scripts or compiled C source code, it made sense to run a
form of UNIX locally. This enables shell scripts to run with no
modifications and the C code to easily recompile. Other user-driven
considerations included access to backup hardware, hard-copy
output, real-time data displays and access to a common library of
software packages.

Upon considering these requirements, our choice was made
simple: it had to be Red Hat Linux. For our purpose, Linux provides
an extremely versatile operating system with the ability to
effortlessly and seamlessly integrate itself efficiently into any
existing network system. The immense amount of supported hardware
made installation on Jim's laptop and on our desktop machines a
painless exercise, and we were delighted with the way that even a
default installation gave us exactly what we wanted. It is this
kind of hardware support and user-friendly installation interface
which caught our eye in the first place when considering various
UNIX systems for Intel processors.

After unpacking our brand new PC (Intel DX 120; 32MB RAM) and
removing the pre-installed OS (we did ask for Linux), the whole
installation took less than an afternoon. We now had a fully
working UNIX workstation configured within the James
Clark Ross NIS domain, auto-mounting file systems
whenever required. Jim went even further with his laptop. Using
Caldera Wabi 2.0, he had the ability to run the BAS standard word
processor and e-mail packages (which are MS Windows-based). Being
able to do all this using free or inexpensive software proves what
a professional product Linux is. Gone are the days when Linux was
considered a “toy UNIX” for hackers—it is now a fully functional
UNIX environment which is just as stable (if not more) as the
various commercial UNIX systems on the market.